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The occurrence of n-saturated, branched, and unsaturated fatty acids of 3 wild terrestrial strains of the genus Chroococcidiopsis (Order Chroococcales): C. supralittoralis, C. umbratilis, and C. versatilis collected from Lake Kinneret, Dead Sea, and Ein Kerem (Jerusalem) was investigated and individual compounds identified by gas chromatography-mass spectrometry. Polar lipids also were examined. Among polar lipids (studied using two-dimensional thin-layer chromatography) were as major glycolipids isolated: monogalactosyl-diacylglycerols, digalactosyl-diacylglycerols, 6-sulfoquinovosyl-diacylglycerols and phosphatidylglycerol. Nonphosphorus betaine-containing lipid, viz. N,N,N-trimethylhomoserin-4-O-yl-diacylglycerol, was found for the first time in cyanobacterial species. 相似文献
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Dembitsky VM 《Bioorganicheskaia khimiia》2002,28(3):196-208
The taxonomic distribution, structure, and biological activity of halogenated alkaloids isolated from marine microorganisms and sponges are reviewed. The structures of nearly 140 natural bromo- and iodo-containing alkaloids are shown. 相似文献
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Natural halogenated fatty acids: their analogues and derivatives 总被引:1,自引:0,他引:1
A comprehensive survey has been made of all fatty acids containing halogen atoms covalently bonded to carbon and which are deemed as naturally occurring. Generally thought to be minor components produced by many different organisms, these interesting compounds now number more than 300. Recent research, especially in the marine area, indicates this number will increase in the future. Sources of halogenated fatty acids include microorganisms, algae, marine invertebrates, and higher plants and some animals. Their possible biological significance has also been discussed 相似文献
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Kaitlen Samse Jacqueline Emathinger Nirmala Hariharan Pearl Quijada Kelli Ilves Mirko V?lkers Lucia Ormachea Andrea De La Torre Amabel M. Orogo Roberto Alvarez Shabana Din Sadia Mohsin Megan Monsanto Kimberlee M. Fischer Walter P. Dembitsky ?sa B. Gustafsson Mark A. Sussman 《The Journal of biological chemistry》2015,290(22):13935-13947
Human cardiac progenitor cells (hCPC) improve heart function after autologous transfer in heart failure patients. Regenerative potential of hCPCs is severely limited with age, requiring genetic modification to enhance therapeutic potential. A legacy of work from our laboratory with Pim1 kinase reveals effects on proliferation, survival, metabolism, and rejuvenation of hCPCs in vitro and in vivo. We demonstrate that subcellular targeting of Pim1 bolsters the distinct cardioprotective effects of this kinase in hCPCs to increase proliferation and survival, and antagonize cellular senescence. Adult hCPCs isolated from patients undergoing left ventricular assist device implantation were engineered to overexpress Pim1 throughout the cell (PimWT) or targeted to either mitochondrial (Mito-Pim1) or nuclear (Nuc-Pim1) compartments. Nuc-Pim1 enhances stem cell youthfulness associated with decreased senescence-associated β-galactosidase activity, preserved telomere length, reduced expression of p16 and p53, and up-regulation of nucleostemin relative to PimWT hCPCs. Alternately, Mito-Pim1 enhances survival by increasing expression of Bcl-2 and Bcl-XL and decreasing cell death after H2O2 treatment, thereby preserving mitochondrial integrity superior to PimWT. Mito-Pim1 increases the proliferation rate by up-regulation of cell cycle modulators Cyclin D, CDK4, and phospho-Rb. Optimal stem cell traits such as proliferation, survival, and increased youthful properties of aged hCPCs are enhanced after targeted Pim1 localization to mitochondrial or nuclear compartments. Targeted Pim1 overexpression in hCPCs allows for selection of the desired phenotypic properties to overcome patient variability and improve specific stem cell characteristics. 相似文献
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The present state of knowledge in the chemistry of mandragora plant is reviewed. Isolations and identifications of the compounds were done from all parts of this plant. Up-to-date more than 80 substances were identified in different species of the genus Mandragora. 相似文献
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Ozone depletion by anthropogenic gases has increased the atmospheric transmission of solar ultraviolet-B radiation (UV-B, 280-315 nm). There is a logical link between the natural defenses of terrestrial and marine organisms against UV radiation and the prevention of UV-induced damage to human skin. UV light degrades organic molecules such as proteins and nucleic acids, giving rise to structural changes that directly affect their biological function. These compounds offer the potential for development of novel UV blockers for human use. The biological role of mycosporine-like amino acids (MAAs) and scytonemin as a defense against solar radiation in organisms, together with their structure, synthesis, distribution, regulation and effectiveness, are reviewed in this article. This review points to the role of MAAs as a natural defense against UV radiation. 相似文献
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Avital Torres Malka Hochberg Inna Pergament Reem Smoum Valerie Niddam Valery M Dembitsky Marina Temina Inka Dor Ovadia Lev Morris Srebnik Claes D Enk 《European journal of biochemistry》2004,271(4):780-784
A novel photo protective mycosporine was isolated from the lichenized ascomycete Collema cristatum. Biological activity was measured in terms of protection against UV-B induced membrane destruction and pyrimidine dimer formation in cultured human keratinocytes, and prevention of UV-B induced erythema. It was found that the pure isolated compound prevented UV-B induced cell destruction in a dose-dependent manner, that the compound partially prevented pyrimidine dimer formation and completely prevented UV-B induced erythema when applied to the skin prior to irradiation. 相似文献
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Valery M. Dembitsky Tomas Rezanka Irina A. Bychek Michail V. Shustov 《Phytochemistry》1991,30(12):4015-4018
Fatty acids of eight lichen species belonging to the genus Cladonia were examined by GC-MS. Twenty-two saturated, 23 monoene, five diene, nine triene and eight tetra-, penta- and hexaene fatty acids were identified. Unusually for lichens, very long-chain fatty acids, 25:1, 26:0, 26:1, 26:3, 28:0, 28:1, and 30:1 were detected. 相似文献
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Abu-Lafi S Odeh I Dewik H Qabajah M Imam A Dembitsky VM Hanus LO 《Biomedical papers of the Medical Faculty of the University Palacky, Olomouc, Czechoslovakia》2007,151(1):21-29
BACKGROUND: A comparative analysis by using static headspace (HS) and steam distillation (SD) GC-MS of the volatile and the semi-volatile secondary metabolites from leaves of cultivated Majorana syriaca. METHODS: The essential oils endogenous to cultivated thyme were isolated and identified by HS-GC-MS technology and compared to those from SD-GC-MS. RESULTS: The HS-GC-MS results showed that the Palestinian cultivated thyme is rich in monoterpene hydrocarbons and phenolic monoterpenes such as alpha-phellandrene, alpha-pinene, beta-myrcene, m-cymene, p-cymene, gamma-terpinene, thymol and carvacrol. In all the samples gamma-terpinene, p-cymene, thymol and carvacrol were the most abundant compounds. CONCLUSIONS: HS and SD-GC-MS have proved that most of the cultivated thyme samples examined has thymol isomer as the major phenolic constituent. 相似文献